1. Field of the Invention
The present invention is related to basic electric elements, and more especially to a relay.
2. Description of the Related Art
A relay includes a yoke assembly, a magnetic steel assembly, a contact system and a shell. The yoke assembly is composed of coils and yokes. The magnetic steel assembly is an integrated one including a cylindrical shaft, a magnetic steel and a plastic armature, and the cylindrical shaft is installed in an axle hole defined by a bottom case of the shell and a tongue-shaped or triangular supporting frame that is plug-connected with a locating and dividing slot board of the magnetic steel assembly inside the shell. The contact system includes movable and immovable contact spring assemblies and a pusher pad that has a slot for insertion of the movable contact spring assembly. There is an obround trepan hole in a front end of the pusher pad for engaging with a push pin which is installed on a pin boss interconnected with a plastic mold envelope of the magnetic steel assembly. One end of each contact spring of the contact system is extended outside the bottom case and connected into an external circuit via bolts. The shell consists of the bottom case and an upper cover, and is shaped approximately like a rectangular case, with locating and dividing slots arranged inside the bottom case according to partitioned part installation area. The relay overcomes the defect that the magnetic steel assembly and the contact system are obstructed by an original rectangular supporting frame and the problem that assembling quality of the magnetic circuit assembly is hard to control for the magnetic latching relay, but the influences of erection stress on internal structural parameters shall be avoided when mounting an electric meter for satisfying requirements of future popularization.
The movable contact spring assembly is one major element in the contact system of the relay. Normally the movable contact spring assembly includes a movable contact spring with a contact at one end and a movable contact spring seat inserted inside the shell of the relay, both of which are connected by three rivets. The contact is arranged in a foreside of the movable contact assembly, and a riveting section on a root of the movable contact spring is connected with that of the movable contact spring seat by lap riveting. Because the movable contact spring is linearly extended in an extension direction of the riveting section of the movable contact spring seat, a long installation section is required inside the shell. In order to fulfill requirements of current density and low power consumption, many back contact springs with partially round arch or “U” shaped convex bends are stacked close to a rear side of the movable contact spring, and front ends of the back contact springs and the movable contact spring are overlapped for riveting the contact, moreover their roots overlapped for being riveted by rivets. Previously the round arch-shaped bends are large and have an unsteady flexibility. Structural pattern of the movable contact spring assembly shall be appropriate and perfect if possible due to its relation to reliability of the contact system of the relay.